Miller and Sale don't have that much in common. Yes, they are both lefties with 3/4 deliveries, but Miller always had amazing stuff with below average to bad control. Sale's stuff isn't as electric, but he knows where it's going. Miller never developed command, that's why he hasn't succeeded yet. Sale is much further along in that department. I don't think a couple of months in the bullpen are going to derail him.
Witness to the agony ('76 Sox season tix) and the ecstasy (2005 World Champions!)